Biodiversity and Evolution 1st Test questions

Complete the following sentence: Introducing new individuals into a small population is an example of ...

gene flow that will increase genetic diversity and most likely help the population.

What term is used to describe all the alleles at every locus for all individuals within a population?

gene pool

Complete the following sentence: The evolution of MRSA is NOT due to ...

directed mutagenesis.

Which of the following should NOT be used as a measure of genetic diversity?

the number of methylated sequences.

When does a hypothesis become a theory?

when several lines of evidence and multiple observations arrive at the same conclusion.

When calculating allele frequencies, what does the chi-square statistic tell us?

whether the gene frequencies in a population differ from random expectations and change through time

How is DNA similar in prokaryotic and eukaryotic cells?

1.In both cells, DNA is a double helix. 2.In both cells, DNA contains the genetic information on how to make proteins for various life functions. 3.In both cells, ribosomes are needed to translate the information in DNA into proteins. 4.In both cells, DNA is made of the same bases. ALL True!!!

Fossilized bones are discovered. Carbon dating indicates that they contain one-fourth the normal amount of carbon-14 found in the bones of a living specimen. The half-life of carbon-14 is 5,730 years. Approximately how old are the bones?

12,000 years

How often does DNA polymerase attach the wrong nucleotide?

1:100,000

What variable in the Hardy-Weinberg equation expresses the heterozygous genotype?

2pq

A population survey shows that 160 out of 250 individuals express the recessive phenotype. What percentage of the population would you predict to be heterozygotes?

32% This answer is correct because if the recessive phenotype is determined by a homozygous recessive genotype, then: q2 = (160/250) = 0.64; therefore, q = 0.8. With q, solve for p: 1 - q = p or 1 - 0.8 = 0.2. To find the frequency of heterozygotes, use 2pq: 2pq = frequency of heterozygotes = 2(0.2)(0.8) = 0.32 or 32%.

Who independently formulated the hypothesis of natural selection before Darwin published his work?

Alfred Russel Wallace

In order to provide access to a new airport, a road was built through a previously undisturbed forest, which isolated a small group of deer from the rest of its population. After several years, conservation biologists determined that 75% of the individuals in the isolated population demonstrated a recessive phenotype that is rare in the rest of the population. How would you determine if this is due to inbreeding or genetic drift?

Compare the number of heterozygotes to homozygotes over time.

Why is the sickle-cell anemia allele more frequent in individuals of sub-Saharan African descent?

Heterozygous individuals have a fitness advantage in sub-Saharan Africa.

What is suggested by comparing the bones in a human arm and a bat's wing?

Humans and bats share a common ancestor.

Which observations formed the basis of Darwin's argument for the theory of natural selection explaining descent with modification outlined in On the Origin of Species?

Individuals vary in heritable traits and produce more offspring than are able to survive, and those offspring compete for limited resources.

Which of the following is true of a cline?

It reflects genetic variation among populations.

Which of the following is the mechanism that drives natural selection?

Individuals with traits better suited to their environments are more likely to survive and reproduce; therefore, their offspring are more likely to inherit these adaptive traits.

Which of the following is a unique property of evolution by gene flow?

It can result in an increase in genetic variation.

Both dragonflies and pigeons have wings. What insight can this fact give us about evolution?

It demonstrates that evolution can give rise to traits that perform similar functions multiple, independent times.

How does the modern system of biological classification differ from that of Linnaeus?

It is based on evolutionary relationships.

Which characteristic makes it least likely that an organism will be preserved in a fossil?

It lived in a tropical rain forest.

Which of the following people proposed a mechanism of evolution before Charles Darwin did?

Jean-Baptiste Lamarck

The fossil record provides direct evidence for evolutionary relationships among living organisms and the history of life. So why is it controversial?

Large gaps in the record suggest there is not enough evidence to support descent with modification.

Which of the following statements is true? 1.Mutations are always passed on to the next generation. 2.Mutations cannot be repaired. 3.Mutations are always harmful. 4.Mutations always result in a change to the phenotype of an organism. . 5.Mutations always alter DNA.

Mutations always alter DNA.

Which of the following population sizes (N) of bison would be most affected by genetic drift?

N = 10.

How is natural selection related to evolution?

Natural selection is one of several mechanisms by which populations evolve.

What is the relationship between natural selection and evolution?

Natural selection is one process that can result in evolution.

Evolution is considered the core theme of biology. Which of the following would NOT be considered a valid argument for why this is so?

Natural selection is the only explanation for the diversity of life.

What is the difference between the honest-advertising and good-genes mechanisms of sexual selection?

Only the good-genes mechanism signals an advantage of a specific trait.

Penguins in Antarctica are superb swimmers, but they walk awkwardly and cannot fly. There is evidence that penguin ancestors could fly long ago. How might natural selection explain this?

Shorter wings may have helped ancestral penguins survive in their environment by enabling them to swim better, and so genes for shorter wings became common.

How does the Church of England's initial response to Darwin's ideas compare with their current position?

The Church was hostile to Darwin's work for many years but now accepts a scientific explanation of evolution.

Which of the following statements is TRUE regarding the effect of a single mutation in one individual on evolution?

The allele can increase in frequency drastically and rapidly.

A population of birds exhibits high diversity in alleles for feather color. Human settlers overhunt the population, causing a bottleneck effect. What might you predict about the population of birds that will exist after the bottleneck event?

The population will have less diversity in feather color because the variety of alleles will be reduced.

A labradoodle is a dog created from the mating of a Labrador retriever, known for its gentle nature, and a poodle, known for its low-shed coat. How does breeding of domesticated animals contrast with natural selection?

They are similar except that in natural selection the traits selected increase a population's fitness, while in artificial selection humans select for a trait that they desire, which may or may not improve the organism's fitness.

Higher genetic variation can be advantageous in which of the following environments?

a changing environment.

Genetic drift can lead to populations with reduced genetic variation. What is one evolutionary consequence of reduced genetic variation?

a decrease in the potential for adaptation to changing environments.

An alternative form of a gene that occurs in the same place on a homologous chromosome (i.e., chromosome pairs of approximately the same length with the same characteristics but each is inherited from a different parent) is ___.

an allele

What was Darwin's interest in joining the mission of the HMS Beagle?

as a companion to the captain of the ship assisting in surveying the geology and biology of sites, primarily in South America.

Why do scientists who explore evolutionary relationships often study ribosomal genes?

because they code for universal features of all organisms.

An endangered falcon population has been closely monitored and cared for in a protected area. Which data would be most appropriate to collect in order to best determine its recovery?

comparison between the protected population and healthy populations of average heterozygosity in a non-coding gene sequence.

A forest fire kills 75% of a shrub population and 100% of the tall trees in an old-growth forest. After some time, the shrubs are much taller than those of a nearby population that was not affected by the fire. What evolutionary mechanism(s) could explain this difference?

genetic drift and/or directional selection.

Natural selection acts on which of the following?

heritable traits and phenotypes.

What influenced Darwin's ideas about the evolution of species during his journey on the surveying mission of the HMS Beagle?

his experience following a major earthquake in Chile.

In his original work on natural selection, Darwin was unable to provide a mechanism to explain which of the following?

inheritance of traits.

Female widow birds prefer males with very long tails. What is this trait an example of?

intersexual selection

Males of Dynastes granti (a beetle) use elongated horns to compete with other males for females. They evolve long horns as a result of which process?

intrasexual selection

Imagine that you are hiking up a mountain and you notice that the trees are gradually becoming larger as you walk. You hypothesize that large size is an adaptation to colder habitats. Which of the following would NOT be informative in supporting or rejecting this hypothesis?

measuring as many trees as possible along the mountain and plotting a graph of the relationship between temperature and tree size.

What type of reproductive behavior is required to maintain Hardy-Weinberg equilibrium?

random mating

Complete the following sentence: Frequency-dependent selection is negative when ...

rare phenotypes have a fitness advantage.

Imagine two human populations that differ in the frequency of a specific cancer gene but are otherwise genetically similar. Which of the following metrics would be the most accurate way to determine the influence of this gene on relative fitness?

total number of children who become reproductive themselves